Indo-US advanced imaging satellite NISAR now on launch pad, lift-off on July 30

NASA-ISRO Synthetic Aperture Radar (NISAR), a joint project to develop and launch a first-of-its-kind high resolution earth imaging satellite has been positioned on the launch pad at the Satish Dhawan Space Centre in Sriharikota.

NISAR is a joint project between the Indian Space Research Organisation (ISRO) and the US’ National Aeronautics and Space Administration (NASA). The satellite is scheduled to be ISRO’s geo-synchronous launch vehicle — F16, which will inject it into a polar sun-synchronous orbit 743 km above earth.

“NISAR is mounted. GSLV-F16 systems checked. Liftoff in 2 days!” ISRO posted on its X handle on Monday evening. This marks the beginning of the final technical tests, pre-launch evaluation and countdown for the launch.

The unique dual-band Synthetic Aperture Radar of NISAR employs advanced and novel techniques which provides high resolution and large swath imagery. NISAR will image the global land and ice-covered surfaces, including islands, sea-ice and selected oceans every 12 days.

According to ISRO, NISAR mission’s primary objectives are to study land and ice deformation, land ecosystems and oceanic regions in areas of common interest to the US and Indian science communities.

Among the tasks envisioned for the NISAR mission are measurement of the woody biomass and its changes, tracking changes in the extent of active crops, understanding the changes in wetlands’ extent, map Greenland’s and Antarctica’s ice sheets, dynamics of sea ice and mountain glaciers, characterise land surface deformation related to seismicity, volcanism, landslides and subsidence and study changes in subsurface aquifers and hydrocarbon reservoirs.

The spacecraft and the launch system have been built by ISRO. It carries two major payloads — the L-band and the S-band SAR. The S-band radar system, data handling and high-speed downlink system has been developed by ISRO, while the L-band radar system, high-speed downlink system, the solid-state recorder, GPS receiver and reflector have been provided by NASA. The 2,392kg satellite will be the first space platform to observe the earth with a dual frequency and detect changes in the planet’s surface down to “fractions of an inch”.

Further, ISRO will handle the satellite commanding and operations whereas NASA will provide the orbit manoeuvre plan and radar operations plan. NISAR mission will be aided with ground station support of both ISRO and NASA for downloading of the acquired images, which after the necessary processing will be disseminated to the users.

NISAR is projected as a civilian project focused on earth observation for scientific purposes, particularly for understanding changes in ecosystems, ice mass, vegetation and natural hazards. Official statements have denied the satellite having any military applications and have hailed it as a milestone in India-US civil space cooperation.